(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
    typeof define === 'function' && define.amd ? define(factory) :
      (global.Stats = factory());
}(this, (function () { 'use strict';

  /**
   * @author mrdoob / http://mrdoob.com/
   */

  var Stats = function () {

    var mode = 0;

    var container = document.createElement( 'div' );
    container.style.cssText = 'position:fixed;top:0;left:0;cursor:pointer;opacity:0.9;z-index:10000';
    container.addEventListener( 'click', function ( event ) {

      event.preventDefault();
      showPanel( ++ mode % container.children.length );

    }, false );

    //

    function addPanel( panel ) {

      container.appendChild( panel.dom );
      return panel;

    }

    function showPanel( id ) {

      for ( var i = 0; i < container.children.length; i ++ ) {

        container.children[ i ].style.display = i === id ? 'block' : 'none';

      }

      mode = id;

    }

    //

    var beginTime = ( performance || Date ).now(), prevTime = beginTime, frames = 0;

    var fpsPanel = addPanel( new Stats.Panel( 'FPS', '#0ff', '#002' ) );
    var msPanel = addPanel( new Stats.Panel( 'MS', '#0f0', '#020' ) );

    if ( self.performance && self.performance.memory ) {

      var memPanel = addPanel( new Stats.Panel( 'MB', '#f08', '#201' ) );

    }

    showPanel( 0 );

    return {

      REVISION: 16,

      dom: container,

      addPanel: addPanel,
      showPanel: showPanel,

      begin: function () {

        beginTime = ( performance || Date ).now();

      },

      end: function () {

        frames ++;

        var time = ( performance || Date ).now();

        msPanel.update( time - beginTime, 200 );

        if ( time > prevTime + 1000 ) {

          fpsPanel.update( ( frames * 1000 ) / ( time - prevTime ), 100 );

          prevTime = time;
          frames = 0;

          if ( memPanel ) {

            var memory = performance.memory;
            memPanel.update( memory.usedJSHeapSize / 1048576, memory.jsHeapSizeLimit / 1048576 );

          }

        }

        return time;

      },

      update: function () {

        beginTime = this.end();

      },

      // Backwards Compatibility

      domElement: container,
      setMode: showPanel

    };

  };

  Stats.Panel = function ( name, fg, bg ) {

    var min = Infinity, max = 0, round = Math.round;
    var PR = round( window.devicePixelRatio || 1 );

    var WIDTH = 80 * PR, HEIGHT = 48 * PR,
      TEXT_X = 3 * PR, TEXT_Y = 2 * PR,
      GRAPH_X = 3 * PR, GRAPH_Y = 15 * PR,
      GRAPH_WIDTH = 74 * PR, GRAPH_HEIGHT = 30 * PR;

    var canvas = document.createElement( 'canvas' );
    canvas.width = WIDTH;
    canvas.height = HEIGHT;
    canvas.style.cssText = 'width:80px;height:48px';

    var context = canvas.getContext( '2d' );
    context.font = 'bold ' + ( 9 * PR ) + 'px Helvetica,Arial,sans-serif';
    context.textBaseline = 'top';

    context.fillStyle = bg;
    context.fillRect( 0, 0, WIDTH, HEIGHT );

    context.fillStyle = fg;
    context.fillText( name, TEXT_X, TEXT_Y );
    context.fillRect( GRAPH_X, GRAPH_Y, GRAPH_WIDTH, GRAPH_HEIGHT );

    context.fillStyle = bg;
    context.globalAlpha = 0.9;
    context.fillRect( GRAPH_X, GRAPH_Y, GRAPH_WIDTH, GRAPH_HEIGHT );

    return {

      dom: canvas,

      update: function ( value, maxValue ) {

        min = Math.min( min, value );
        max = Math.max( max, value );

        context.fillStyle = bg;
        context.globalAlpha = 1;
        context.fillRect( 0, 0, WIDTH, GRAPH_Y );
        context.fillStyle = fg;
        context.fillText( round( value ) + ' ' + name + ' (' + round( min ) + '-' + round( max ) + ')', TEXT_X, TEXT_Y );

        context.drawImage( canvas, GRAPH_X + PR, GRAPH_Y, GRAPH_WIDTH - PR, GRAPH_HEIGHT, GRAPH_X, GRAPH_Y, GRAPH_WIDTH - PR, GRAPH_HEIGHT );

        context.fillRect( GRAPH_X + GRAPH_WIDTH - PR, GRAPH_Y, PR, GRAPH_HEIGHT );

        context.fillStyle = bg;
        context.globalAlpha = 0.9;
        context.fillRect( GRAPH_X + GRAPH_WIDTH - PR, GRAPH_Y, PR, round( ( 1 - ( value / maxValue ) ) * GRAPH_HEIGHT ) );

      }

    };

  };

  return Stats;

})));
